Module F Flashcards
List and describe the functions of the 4 hormones produced by the endocrine pancreas
- Insulin: produced by beta cells. Increases glucose uptake, storage, and utilization, lowering blood glucose
- Glucagon: produced by alpha cells. Inhibits insulin activity and promotes glycogenolysis and gluconeogenesis, increasing blood glucose.
- Pancreatic polypeptide: facilitates digestive processes, exact functions unclear
- Amylin: function is unknown
Describe general features of the pathophysiology, onset, and signs/symptoms of type 1 diabetes
- rapid onset (over a few weeks)
- Ususally juvenile onset, but may be later
- severe insulin depletion
- increased circulating glucagon (insulin inhibits glucagon secretion)
- May cause ketoacidosis
oral hypoglycemics generally ______ (are / are not) effective in management of type 1 NIDDM
are not!
Insulin ______ (can / can not) be given orally
can not
it is a polypeptide and is hydorlyzed in the GIT
1 unit (u) of insulin is defined as:
the amount required to mobilize 10g of dietary carbohydrates
Outline 4 major physiologic effects of insulin
- Inhibits glycogenolyis and promotes glycogenesis in the liver and skeletal muscles
- Promotes glucose uptake in liver and skeletal muscles by up-regulating GLUT transporters
- Promotes utilization of glucose for ATP production in skeletal muscle
- Promotes lipogenesis from glucose in adipose tissue
Compare circulating insulin, glucagon, glucose, and ketone levels in patients with unmanaged type 1 vs type 2 diabetes
- Type 1: Insulin = low, glucagon = high, glucose = high, ketones = high
- Type 2: Insulin = high, glucagon = low, glucose = high, ketones = low
The 5 classes of insulin analogues are:
- rapid-acting
- short-acting
- intermediate-acting
- long-acting
- inhaled
The class of insulin analogue used to control post-prandial blood glucose is ________
Rapid-acting
Rapid-acting insulins (novolog, humalog), are often combined with a ________
long-acting insulin (Glargine/lantus)
The only class of insulin suitable for IV injection during DKA is _______
short-acting
short-acting insulin ______ (is / is not) suitable for post-prandial glucose control because:
is not, because the onset is too slow and duration too short so it causes post-prandial hyperglycemia followed by reflex hypoglycemia
The cheapest form of insulin preparation is _________. The drawbacks of this formulation are:
intermediate acting. Drawbacks are no consistent absorption, and much interpatient variability in activity
Long-acting insulin (glargine/lantus) may be released over a period of ______. It is used to control _____ (basal / post-prandial) insulin levels and is often combined with _____
24hrs. Basal insulin levels. A rapid acting insulin
Describe the function and advantages of inhaled insulins
used in place of rapid or short-acting insulins. Advantage is that it doesn’t require SC injection and therefore may lead to better patient adherence.
The two classes of insulin secretagogues are:
sulfonylureas and meglinitides
The mechanism of action of sulfonylurea drugs is:
they increase pulsatile (not basal) insulin secretion and decrease glucagon production. They also increase insulin sensitivity somewhat in type 2 DM
The major adverse effects of sulfonylurea drugs (glyburide, etc.) are:
- hypoglycemia with increased activity or skipped meals
- skin rashes, N/V, hematologic effects
- many drug interactions
The drugs of choice in treating type 2 diabetes are:
metformin
Describe the MOA and administration of meglinitide agents
they increase insulin secretion over a 3-4 hour period. They are taken orally pre-prandially
The most commonly used oral hypoglycemic is:
metformin
sulfonylureas _____ (may / may not) be co-administered with a meglinitide. Either insulin secretagogue _____ (may / may not) be combined with metformin
may not. May
Describe the MOA of metformin
- primarily inhibits liver gluconeogensis
- Increases insulin sensitivity by promoting insulin-receptor binding and up-regulating GLUT-4 transporter production
- inhibits glucose absorption from the GIT
The first-line therapy for all type 2 diabetes is:
diet and lifestyle changes
Describe the two major clinical uses of vasopressin
- Used as an antidiuretic to treat states of extreme water excretion such as diabetes insipidus
- Used as a vasoconstrictor to manage hypotension due to V1 receptor binding in smooth muscle
Contrast the effects of V1 and V2 receptor binding by vasopressin
- V1: found in vascular smooth muscle. Binding causes vasoconstriction and increased BP
- V2: found in renal collecting ducts. Cause aquaporin production on luminal surface of CD, increased water retention and concentration of urine. Leads to increased blood volume and increased BP
